摘要
本文以高强钢表面海洋微生物膜层为研究对象,开展了激光清洗试验与数值模拟研究.基于激光清洗常用的数值建模思想建立激光辐照模型,并改进了材料的去除过程从而建立了激光烧蚀模型,采用两种模型计算比较了功率200~800 W,频率10和20 kHz下激光清洗的温度场和清洗轮廓,并分析了不同光斑搭接率对清洗质量的影响.结果表明:功率为600 W时激光辐照模型计算的清洗宽度达906μm,明显超过了光斑直径900μm,而激光烧蚀模型仅有882μm且功率增大到800 W也没有超过光斑直径. 200 W功率下激光清洗实验测得的最高温度约为423.5 K,激光烧蚀模型计算值为432 K,而激光辐照模型计算值高达2441 K. 200 W功率下激光清洗实验测得的清洗深度约为33.7μm,激光烧蚀模型计算值约为32.6μm,而激光辐照模型计算值高达63.9μm;因此结合试验和理论计算分析结果表明激光烧蚀模型相较激光辐照模型精确度更高.此外,采用激光烧蚀模型对5~10 kHz频率激光清洗表面进行模拟,结果显示:在采用经典高斯能量分布激光束进行激光清洗时,应保持光斑搭接率在50%以上,以保证清洗质量均匀一致.
A laser-cleaning experiment and numerical simulation of marine microbial films on high-strength steel were performed. In this study,a “Laser Irradiation” model was established based on the common numerical modeling idea of laser cleaning, and a “Laser Ablation”model was developed by improving the material removal process. The temperature field and surface profile of laser cleaning with a power range of 200–800 W and a frequency of 10–20 k Hz were calculated and compared using two models. The effect of spot lap rate on cleaning quality was analyzed. The results indicated that the width of the cleaned area calculated by the laser irradiation model was906 μm at a power of 600 W, which was notably larger than the spot diameter of 900 μm. The width of the cleaned area calculated by the laser ablation model was only 882 μm, and even when the power was increased to 800 W, it did not exceed the spot diameter. The maximum temperature measured in the laser-cleaning experiment at 200 W was about 423.5 K;moreover, the values calculated by the laser ablation and laser irradiation models were about 432 and 2441 K, respectively. The maximum depth of the cleaned area measured in the laser-cleaning experiment at 200 W was about 33.7 μm, and the values calculated by the laser ablation and laser irradiation models were about 32.6 and 63.9 μm, respectively. Therefore, the experimental and theoretical analysis results indicate that the laser ablation model is more accurate than the laser irradiation model. The laser ablation model was also used to simulate the surface profile after laser cleaning in the frequency range of 5–10 k Hz. The results show that when a laser beam with classical Gaussian energy distribution is used for laser cleaning, the spot overlap ratio should be kept above 50% to ensure uniform cleaning quality.
作者
冯俊华
毕思源
雷正龙
付伟杰
薛跃文
FENG JunHua;BI SiYuan;LEI ZhengLong;FU WeiJie;XUE YueWen(State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology,Harbin 150001,China)
出处
《中国科学：技术科学》
EI
CSCD
北大核心
2024年第1期165-178,共14页
Scientia Sinica(Technologica)
基金
国家自然科学基金(批准号:52175391)资助项目。
关键词
海洋生物膜层处理
激光清洗
表面轮廓
数值模拟
treatment of marine biofilm layer
laser cleaning
surface profile
numerical simulation
